ASSESSMENT OF PLATELET ACTIVATION BY CORONARY SINUS BLOOD-SAMPLING DURING BALLOON ANGIOPLASTY AND DIRECTIONAL CORONARY ATHERECTOMY

Three markers of platelet activation (platelet-derived microparticles, fibrinogen binding and expression of P-selectin) were assessed by flo w cytometry during diagnostic coronary angiography and therapeutic cor onary interventions. In 24 patients undergoing diagnostic angiography, blood was collected to determine if our sampling techniques or corona ry angiography caused platelet activation. Changes during diagnostic a ngiography were used to establish baseline values and interpret change s during coronary interventions. In 21 patients, blood samples were ob tained at 5 time points during percutaneous transluminal coronary angi oplasty (PTCA) (n = 17) or directional coronary atherectomy (DCA) (n = 4). During coronary interventions, mean values for the percentage of platelets expressing P-selectin or binding fibrinogen increased, but w ith considerable variation among patients. Individual responses for pl atelet activation markers in each patient were characterized using a t wofold increase to indicate elevation related to the intervention, Pat ients were classified as having complicated or uncomplicated procedure s based on the presence of acute closure, dissection, or thrombus obse rved by angiography. There were no differences in the percentage of el evated markers between patients with uncomplicated (12.5%) and complic ated (19%) PTCA procedures. However, patients treated with DCA had mor e elevated markers (38%) than those treated with PTCA (15%) (p = 0.04) . Our data suggest that the extent of platelet activation in individua l patients cannot be predicted by common angiographic findings or comp lications. More markers of platelet activation were present after DCA and may reflect a greater degree of vascular trauma associated with th is procedure. (C) 1997 by Excerpta Medica, Inc.